Palladium-Catalyzed Carbene Migratory Insertion and Trapping with Sulfinic Acid Salts toward Allylic Sulfones.

Allylic sulfones were synthesized with excellent selectivity and good yield via Pd-catalyzed cross-coupling of vinyl iodide with N-tosylhydrazone. This process involves palladium carbene migratory insertion/trapping with sulfinic acid salts. For the previous Pd-catalyzed N-tosylhydrazone cross-coupling, sulfinic acid salt is generated as a byproduct. In this transformation, the diazo compound and the sulfinic acid salt, which are all generated from N-tosylhydrazone, were used as cross-coupling partner.